A belted absorbent garment usually comprises a front body panel adapted to be applied over the stomach of a user, a back body panel adapted to be applied over the back of the user and a crotch portion adapted to extend over the crotch of the user between his/her legs. The belted absorbent garment further comprises opposed laterally extending belt sections attached to the waist portion of the back body panel. The belt sections are adapted to be wrapped around the waist of the user of the garment and are fastened together after which the front body panel is fastened to the external surface of the belt in such a way that the garment will assume a pant-like shape. Examples of belted absorbent garments may for example be found in European patent applications no. EP-A-0287388, EP-A-0409307, EP-A-0605012 and French patent application no. FR-A-2586558.
As a user moves about (i.e. eats, breathes, sneezes, walks etc.), the circumference of the user's waist expands and contracts, which consequently results in the belt sections being strained and relaxed. Repeated or exaggerated expansion and contraction of the belt sections can lead to permanent deformation of the belt sections and thus result in the length of the belt being irreversibly increased, which in turn may result in the absorbent garment slipping down from the user's waist and, in the worst case, falling off the user.
It is known to provide an absorbent garment with a belt made entirely of elastic material, however elastic material is generally more expensive than inelastic material, it is much more difficult to attach fastening means, such as hooks, to an elastic material and an elastic belt is not as easy for a user to handle as an inelastic belt. Absorbent garments comprising partly elastic belts, whereby a belt is provided with at least one elastic panel, are also known, for example through Japanese patent no. JP-B-3471999 and European patent no. EP-B-0487758. However known belted absorbent garments have a tendency to slip down from a user's waist if subjected to repeated or exaggerated expansion and contraction.
When a user purchases a belted absorbent garment it is not possible for him/her to predict how well the belt of the absorbent garment will maintain its original circumference when in use and consequently how well the belted absorbent garment will stay in place since test methods according to the prior art do not provide such information. Only test specimens cut from the fabrics that constitute a belted absorbent garment are tested in known test methods.
British patent no. GB 2389665, for example, discloses a method for determining the stretch and recovery characteristics of fabrics, in particular stretch fabrics. The method comprises the steps of mounting a fabric test piece into a clamping frame and mounting the clamping frame together with its fabric test piece in a stretching device. The fabric is deformed by flexing it a pre-determined number of times at a pre-determined speed. The patent further discloses equipment for simulating the stretch and recovery characteristics of fabrics during their normal use. The equipment comprises a clamping device to retain and support a test piece of fabric, a hemispherical block beside which the fabric is positioned and a geared motor and crank arrangement to move the hemispherical block laterally in order to stretch the fabric. A fabric test piece may be repeatedly stretched and relaxed a predetermined number of times, as would occur in actual user use.
U.S. Pat. No. 4,366,814 discloses an elastic bandage material. 1-inch wide strips of test material are mounted in the jaws of an Instron tensile tester and stretched to the desired percent elongation. The strip is then allowed to recover by decreasing the distance through which it has been stretched.
A disadvantage with testing only a test specimen of fabric is that a belted absorbent garment usually comprises several different parts comprising various materials, which are used to fasten the belted absorbent garment around a user's waist, such as adhesive tape, elasticated sections, elastic panels and other attached or integrated belt elements. It is therefore difficult to determine the net elastic and tensile properties of all of said parts/materials from an analysis of each part/material separately. Furthermore, the weight of a belted absorbent garment and its contents are not taken into account in the tests carried out on a test specimen, even though the weight of a belted absorbent garment and its contents will influence how well the belted absorbent garment stays in place on a user.